The celebration of the anniversary of one's birth is a phenomenon of modern industrial society. It is connected to the rise of a scientific way of thinking and to new attitudes about children and childhood. Perfection of the calendar by the Egyptians and Mesopotamians enabled people to reckon exact birth dates, but ancient and classical cultures rarely celebrated birthdays, except for those of royalty. The early Catholic Church deemed birthday festivities to be pagan; more important was the name day, the commemoration of the patron saint whose name was attached to a child upon baptism. After the Protestant Reformation, Western cultures celebrated birthdays of royalty, presidents, and war heroes, but common folk seldom used the occasion of their own birth for special notice. Native societies in Africa and America rarely kept records of age, and therefore did not observe birthdays except for special rites of passage, usually from childhood to adulthood. In the East, Chinese families often recognized birthdays, though mainly for adults; the Japanese, on the other hand, often collapsed all birthdays to New Year's Day, which they made into a common celebratory event.
By the mid-nineteenth century, the official collection of demographic data, most notably birth certification, decennial censuses, and other public surveys that listed exact date of birth, as well as the recording of birth and baptismal dates in family bibles, prompted more ordinary people to identify and observe their birthday. Still, the occasion seldom involved special ritual. Diaries and reminiscences of American children either omitted recognition of birthdays or mentioned them only in passing without reference to gifts or parties. Certain customs, however, were taking hold. German families, for example, feasted on Geburtstagtorten, birthday cakes, usually eaten at a party.
New attitudes about the worth and special qualities of children helped to transform birthdays into elaborate rituals in the late nineteenth century. Influenced by the Romantics, who emphasized feeling over reason, along with a decline in infant and child mortality, writers and parents began to dote on and cherish children as well as treat them in ways separate from adults. Such treatment often meant indulgences that formerly had not existed. Birthdays presented occasions for such indulgence. By the 1870s, wealthy families were holding elaborate children's birthday parties, and birthday books, in which children listed the birthdays of friends and relatives, circulated widely. Parties and cakes became common among rural and working-class families as well. Customs such as birthday spankings for good luck and wishing on the candles of the birthday cake before blowing them out became customary. Perhaps more importantly, new attitudes about measurement and time induced people to begin using the birthday to measure their experiences and accomplishments relative to peers and to social expectations. A child who had not lost all baby teeth or contracted certain childhood diseases by a particular birthday was said to be "behind schedule"; one who was in an advanced school grade or had grown taller than peers by a certain age was "ahead of schedule."
As the twentieth century progressed, commercial interests increasingly responded to the new popularity of birthday celebrations, especially for children. Birthday cards, adapted from Christmas and greeting cards of the nineteenth century, contained ever more elaborate messages and later included representations of characters in children's popular culture such as Mickey Mouse and the Peanuts comic strip characters. Decorations, hats, party favors, and gift wrap became birthday staples, and "Happy Birthday to You" by the sisters Mildred J. Hill and Patty Smith Hill became the most commonly performed song in the English language. For children, a birthday remains one of the most anticipated celebrations of the year, a rite fraught with expectations of privilege and indulgence that reflect their special status in the family and society.